Wanadoo in customer data security breach

A security breach at one of the biggest internet service providers in the UK led to thousands of customers' private details being made public, it has emerged.

Wanadoo, which has 2 million internet subscribers in Britain, admitted that a technical mistake led to swaths of customer account information - including their real names and passwords - being published online.

"Wanadoo would like to reassure customers that this was an isolated incident and as soon as we were made aware of the problem, the information was removed from the public domain," the company said in a statement. "An investigation is currently taking place to uncover how this happened."

A spokesman for the company said that the leak was fixed as soon as technicians became aware of the problem last week - but admitted that they had no idea how long it had existed for. Internet postings from some customers speculated that the loophole, which seems to have emanated from Portugal, may have lain undiscovered for as long as two years.

Around 20,000 customers are believed to have been affected directly, although red-faced officials refused to confirm exact numbers. It is not clear exactly what information had been mistakenly published, but it is believed that affected customers had their real name, email address, user name and password all put online.

As a result of the breach, the company's chief executive, Eric Abensur, was forced to send an email message directly to customers, urging those affected to change their passwords as soon as possible.

"Any compromise of the security and integrity of our service is unacceptable," Mr Abensur told subscribers.

It is not the first time an internet company operating in the UK has mistakenly published customer information. Last year Tiscali was forced to apologise after mistakenly displaying the name, address and contact information of random subscribers.

"I feel that any company dealing with technology at this level should be far more aware of security, and yet it seems that it has been grossly neglected at the expense of the customer," said one customer. "If an ISP is making mistakes of this magnitude, how can any of its users ever hope to be safe?"

The incident has caused consternation at Wanadoo, which was originally set up as pioneering service provider Freeserve before being bought by France Telecom six years ago.

The parent company recently announced plans to axe 2,000 Wanadoo jobs as part of a restructuring. The company will be folded into the Orange brand this summer as its French owners look to converge their mobile and online businesses.